Lecture 23: Transport in Vascular Plants

Question 1

how does water climb trees?

Answer 1

capillary action
transpiration
root presure

Question 2

what does capillary action use to work?

Answer 2

secondary xylem (tracheids/vessel elements), thin tube = greater length of transport!

Question 3

how does transpiration work?

Answer 3

water potential
strength of water column
through leaves and canopy!

Question 4

how does root pressure work to allow water to climb trees?

Answer 4

water enters roots via osmosis

Question 5

what are the three transport routes for water/solutes? where do they go?

Answer 5

1. apoplastic route (through cell wall)
2. symplastic route (through cytosol: within cell)
3. transmembrane route (across cell wall and plasma membrane)

Question 6

how does water potential work?

Answer 6

high water potential (negative) to low water potential (VERY negative)

Question 7

_____ determines the direction of water movement and the water’s capacity to do work

Answer 7

water potential

Question 8

when osmosis occurs in a flaccid plant…

Answer 8

plant gains water and becomes turgid

Question 9

turgor loss in plants results in ____

Answer 9

wilting

Question 10

changes in turgor pressure opens/closes the _____

Answer 10

stomata

Question 11

when plant is turgid, stomata….

Answer 11

opens pore as guard cells bow outwards

Question 12

when a plant is flaccid, stomata…

Answer 12

closes pore

Question 13

how are guard cells controlled?

Answer 13

with potassium

Question 14

____ is needed for efficient long-distance transport

Answer 14

bulk flow

Question 15

the ____ is the last checkpoint for passage of minerals into vascular tissue

Answer 15

endodermis

Question 16

the ____ is waxy and made of _____… it blocks the apoplastic transfer of minerals within plant cells

Answer 16

casparian strip, suberin

Question 17

_____ is the evaporation of water from a plant’s surface

Answer 17

transpiration

Question 18

____ of water creates negative pressure potential

Answer 18

surface tension

Question 19

what is the path of water uptake to adhesion/cohesion in xylem, to transpiration of water?

Answer 19

soil - roots - cohesion/adhesion in xylem - end of xylem in leaves - mesophyll - intercellular spaces in between spongy mesophyll - stomata - atmosphere

Question 20

____ is when products of photosynthesis are transported through phloem

Answer 20

translocation

Question 21

the path of translocation is from a ____ to a _____

Answer 21

sugar source to sugar sink

Question 22

____ is an aqueous solution, high in sucrose

Answer 22

phloem sap

Question 23

a ____ is where sugars are made

Answer 23

sugar source

Question 24

where are sugars made in plants?

Answer 24

chloroplasts in leaves!

Question 25

a ____ is where sugars end up

Answer 25

sugar sink (fruits/seeds/roots)

Question 26

why do we need sugar sinks?

Answer 26

because not every area of the plant can photosynthesize and make its own sugars